1. Field of the Invention
This invention relates to a valve and in particular to the structure of a temperature responsive valve for pollution control of an internal combustion engine.
2. Description of the Prior Art
In the past it has been conventional for temperature responsive valves to be connected to the coolant system of an internal combustion engine and the various vacuum ports of the valve to be interconnected to the spark advance device, the manifold vacuum and/or the carburetor vacuum of the internal combustion engine for the purpose of controlling the emission of pollutants from the engine while at the same time preventing overheating of the engine coolant system especially when the engine is being operated at an idle speed.
U.S. Pat. Nos. 3,436,017; 3,540,422, 3,738,571 and 3,750,639 are representative of the prior art in illustrating the variety of temperature responsive valves.
One of the problems associated with the prior art temperature responsive valves is that even though the prior art temperature responsive valves as manufactured were of relatively simple construction they were susceptible, after repeated and prolonged use, of leakage and therefore would eventually perform non-satisfactorily in minimizing pollutants emitted from an internal combustion engine operating at an idle position.